The growing complexity of System-on-Chip (SoC) design calls for an increased usage of transaction-level modeling (TLM), high-level synthesis tools, and reuse of pre-designed components. In the framework of a compositional methodology for efficient SoC design exploration the authors present three main contributions: a concise library format for characterization and reuse of components specified in high-level languages like SystemC; an algorithm to prune alternative implementations of a component given the context of a specific SoC design; and an algorithm that explores compositionally the design space of the SoC and produces a detailed plan to run high-level synthesis on its components for the final implementation. The two algorithms are computationally efficient and enable an effective parallelization of the synthesis runs.